x86: also discard .fini_array in linker script

This simply parallels .dtors. Both section types can reference
.text.exit, which requires them to be discarded together with that one.
Compilers, depending on their findings during the configure phase, may
elect to use either model. While .{init,fini}_array look to be
preferred, cross compilers apparently have this guessed, likely
resulting in a fallback to .{c,d}tors. Hence we need to support both
sets.

Fixes: 4b7fd8153d ("x86: fold sections in final binaries")
Reported-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

xen/arch/x86/xen.lds.S

@@ -414,6 +414,8 @@ SECTIONS
        *(.eh_frame)
        *(.dtors)
        *(.dtors.*)
+       *(.fini_array)
+       *(.fini_array.*)
 #ifdef EFI
        *(.comment)
        *(.comment.*)